1/*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Casey Leedom of Lawrence Livermore National Laboratory.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
|
36 * $FreeBSD: head/lib/libc/gen/getcap.c 55837 2000-01-12 09:23:48Z jasone $
|
| 36 * $FreeBSD: head/lib/libc/gen/getcap.c 56698 2000-01-27 23:07:25Z jasone $ |
37 */
38
39#if defined(LIBC_SCCS) && !defined(lint)
40static char sccsid[] = "@(#)getcap.c 8.3 (Berkeley) 3/25/94";
41#endif /* LIBC_SCCS and not lint */
42
43#include <sys/types.h>
44
45#include <ctype.h>
46#include <db.h>
47#include <errno.h>
48#include <fcntl.h>
49#include <limits.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <unistd.h>
54
55#define BFRAG 1024
56#define BSIZE 1024
57#define ESC ('[' & 037) /* ASCII ESC */
58#define MAX_RECURSION 32 /* maximum getent recursion */
59#define SFRAG 100 /* cgetstr mallocs in SFRAG chunks */
60
61#define RECOK (char)0
62#define TCERR (char)1
63#define SHADOW (char)2
64
65static size_t topreclen; /* toprec length */
66static char *toprec; /* Additional record specified by cgetset() */
67static int gottoprec; /* Flag indicating retrieval of toprecord */
68
69static int cdbget __P((DB *, char **, char *));
70static int getent __P((char **, u_int *, char **, int, char *, int, char *));
71static int nfcmp __P((char *, char *));
72
73/*
74 * Cgetset() allows the addition of a user specified buffer to be added
75 * to the database array, in effect "pushing" the buffer on top of the
76 * virtual database. 0 is returned on success, -1 on failure.
77 */
78int
79cgetset(ent)
80 char *ent;
81{
82 if (ent == NULL) {
83 if (toprec)
84 free(toprec);
85 toprec = NULL;
86 topreclen = 0;
87 return (0);
88 }
89 topreclen = strlen(ent);
90 if ((toprec = malloc (topreclen + 1)) == NULL) {
91 errno = ENOMEM;
92 return (-1);
93 }
94 gottoprec = 0;
95 (void)strcpy(toprec, ent);
96 return (0);
97}
98
99/*
100 * Cgetcap searches the capability record buf for the capability cap with
101 * type `type'. A pointer to the value of cap is returned on success, NULL
102 * if the requested capability couldn't be found.
103 *
104 * Specifying a type of ':' means that nothing should follow cap (:cap:).
105 * In this case a pointer to the terminating ':' or NUL will be returned if
106 * cap is found.
107 *
108 * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
109 * return NULL.
110 */
111char *
112cgetcap(buf, cap, type)
113 char *buf, *cap;
114 int type;
115{
116 register char *bp, *cp;
117
118 bp = buf;
119 for (;;) {
120 /*
121 * Skip past the current capability field - it's either the
122 * name field if this is the first time through the loop, or
123 * the remainder of a field whose name failed to match cap.
124 */
125 for (;;)
126 if (*bp == '\0')
127 return (NULL);
128 else
129 if (*bp++ == ':')
130 break;
131
132 /*
133 * Try to match (cap, type) in buf.
134 */
135 for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
136 continue;
137 if (*cp != '\0')
138 continue;
139 if (*bp == '@')
140 return (NULL);
141 if (type == ':') {
142 if (*bp != '\0' && *bp != ':')
143 continue;
144 return(bp);
145 }
146 if (*bp != type)
147 continue;
148 bp++;
149 return (*bp == '@' ? NULL : bp);
150 }
151 /* NOTREACHED */
152}
153
154/*
155 * Cgetent extracts the capability record name from the NULL terminated file
156 * array db_array and returns a pointer to a malloc'd copy of it in buf.
157 * Buf must be retained through all subsequent calls to cgetcap, cgetnum,
158 * cgetflag, and cgetstr, but may then be free'd. 0 is returned on success,
159 * -1 if the requested record couldn't be found, -2 if a system error was
160 * encountered (couldn't open/read a file, etc.), and -3 if a potential
161 * reference loop is detected.
162 */
163int
164cgetent(buf, db_array, name)
165 char **buf, **db_array, *name;
166{
167 u_int dummy;
168
169 return (getent(buf, &dummy, db_array, -1, name, 0, NULL));
170}
171
172/*
173 * Getent implements the functions of cgetent. If fd is non-negative,
174 * *db_array has already been opened and fd is the open file descriptor. We
175 * do this to save time and avoid using up file descriptors for tc=
176 * recursions.
177 *
178 * Getent returns the same success/failure codes as cgetent. On success, a
179 * pointer to a malloc'ed capability record with all tc= capabilities fully
180 * expanded and its length (not including trailing ASCII NUL) are left in
181 * *cap and *len.
182 *
183 * Basic algorithm:
184 * + Allocate memory incrementally as needed in chunks of size BFRAG
185 * for capability buffer.
186 * + Recurse for each tc=name and interpolate result. Stop when all
187 * names interpolated, a name can't be found, or depth exceeds
188 * MAX_RECURSION.
189 */
190static int
191getent(cap, len, db_array, fd, name, depth, nfield)
192 char **cap, **db_array, *name, *nfield;
193 u_int *len;
194 int fd, depth;
195{
196 DB *capdbp;
197 register char *r_end, *rp, **db_p;
198 int myfd, eof, foundit, retval, clen;
199 char *record, *cbuf;
200 int tc_not_resolved;
201 char pbuf[_POSIX_PATH_MAX];
202
203 /*
204 * Return with ``loop detected'' error if we've recursed more than
205 * MAX_RECURSION times.
206 */
207 if (depth > MAX_RECURSION)
208 return (-3);
209
210 /*
211 * Check if we have a top record from cgetset().
212 */
213 if (depth == 0 && toprec != NULL && cgetmatch(toprec, name) == 0) {
214 if ((record = malloc (topreclen + BFRAG)) == NULL) {
215 errno = ENOMEM;
216 return (-2);
217 }
218 (void)strcpy(record, toprec);
219 myfd = 0;
220 db_p = db_array;
221 rp = record + topreclen + 1;
222 r_end = rp + BFRAG;
223 goto tc_exp;
224 }
225 /*
226 * Allocate first chunk of memory.
227 */
228 if ((record = malloc(BFRAG)) == NULL) {
229 errno = ENOMEM;
230 return (-2);
231 }
232 r_end = record + BFRAG;
233 foundit = 0;
234 /*
235 * Loop through database array until finding the record.
236 */
237
238 for (db_p = db_array; *db_p != NULL; db_p++) {
239 eof = 0;
240
241 /*
242 * Open database if not already open.
243 */
244
245 if (fd >= 0) {
246 (void)lseek(fd, (off_t)0, SEEK_SET);
247 myfd = 0;
248 } else {
249 (void)snprintf(pbuf, sizeof(pbuf), "%s.db", *db_p);
250 if ((capdbp = dbopen(pbuf, O_RDONLY, 0, DB_HASH, 0))
251 != NULL) {
252 free(record);
253 retval = cdbget(capdbp, &record, name);
254 if (retval < 0) {
255 /* no record available */
256 (void)capdbp->close(capdbp);
257 return (retval);
258 }
259 /* save the data; close frees it */
260 clen = strlen(record);
261 cbuf = malloc(clen + 1);
262 memcpy(cbuf, record, clen + 1);
263 if (capdbp->close(capdbp) < 0) {
264 free(cbuf);
265 return (-2);
266 }
267 *len = clen;
268 *cap = cbuf;
269 return (retval);
270 } else {
|
271 fd = _libc_open(*db_p, O_RDONLY, 0);
|
| 271 fd = _open(*db_p, O_RDONLY, 0); |
272 if (fd < 0)
273 continue;
274 myfd = 1;
275 }
276 }
277 /*
278 * Find the requested capability record ...
279 */
280 {
281 char buf[BUFSIZ];
282 register char *b_end, *bp;
283 register int c;
284
285 /*
286 * Loop invariants:
287 * There is always room for one more character in record.
288 * R_end always points just past end of record.
289 * Rp always points just past last character in record.
290 * B_end always points just past last character in buf.
291 * Bp always points at next character in buf.
292 */
293 b_end = buf;
294 bp = buf;
295 for (;;) {
296
297 /*
298 * Read in a line implementing (\, newline)
299 * line continuation.
300 */
301 rp = record;
302 for (;;) {
303 if (bp >= b_end) {
304 int n;
305
|
306 n = _libc_read(fd, buf, sizeof(buf));
|
| 306 n = _read(fd, buf, sizeof(buf)); |
307 if (n <= 0) {
308 if (myfd)
|
309 (void)_libc_close(fd);
|
| 309 (void)_close(fd); |
310 if (n < 0) {
311 free(record);
312 return (-2);
313 } else {
314 fd = -1;
315 eof = 1;
316 break;
317 }
318 }
319 b_end = buf+n;
320 bp = buf;
321 }
322
323 c = *bp++;
324 if (c == '\n') {
325 if (rp > record && *(rp-1) == '\\') {
326 rp--;
327 continue;
328 } else
329 break;
330 }
331 *rp++ = c;
332
333 /*
334 * Enforce loop invariant: if no room
335 * left in record buffer, try to get
336 * some more.
337 */
338 if (rp >= r_end) {
339 u_int pos;
340 size_t newsize;
341
342 pos = rp - record;
343 newsize = r_end - record + BFRAG;
344 record = reallocf(record, newsize);
345 if (record == NULL) {
346 errno = ENOMEM;
347 if (myfd)
|
348 (void)_libc_close(fd);
|
| 348 (void)_close(fd); |
349 return (-2);
350 }
351 r_end = record + newsize;
352 rp = record + pos;
353 }
354 }
355 /* loop invariant let's us do this */
356 *rp++ = '\0';
357
358 /*
359 * If encountered eof check next file.
360 */
361 if (eof)
362 break;
363
364 /*
365 * Toss blank lines and comments.
366 */
367 if (*record == '\0' || *record == '#')
368 continue;
369
370 /*
371 * See if this is the record we want ...
372 */
373 if (cgetmatch(record, name) == 0) {
374 if (nfield == NULL || !nfcmp(nfield, record)) {
375 foundit = 1;
376 break; /* found it! */
377 }
378 }
379 }
380 }
381 if (foundit)
382 break;
383 }
384
385 if (!foundit)
386 return (-1);
387
388 /*
389 * Got the capability record, but now we have to expand all tc=name
390 * references in it ...
391 */
392tc_exp: {
393 register char *newicap, *s;
394 register int newilen;
395 u_int ilen;
396 int diff, iret, tclen;
397 char *icap, *scan, *tc, *tcstart, *tcend;
398
399 /*
400 * Loop invariants:
401 * There is room for one more character in record.
402 * R_end points just past end of record.
403 * Rp points just past last character in record.
404 * Scan points at remainder of record that needs to be
405 * scanned for tc=name constructs.
406 */
407 scan = record;
408 tc_not_resolved = 0;
409 for (;;) {
410 if ((tc = cgetcap(scan, "tc", '=')) == NULL)
411 break;
412
413 /*
414 * Find end of tc=name and stomp on the trailing `:'
415 * (if present) so we can use it to call ourselves.
416 */
417 s = tc;
418 for (;;)
419 if (*s == '\0')
420 break;
421 else
422 if (*s++ == ':') {
423 *(s - 1) = '\0';
424 break;
425 }
426 tcstart = tc - 3;
427 tclen = s - tcstart;
428 tcend = s;
429
430 iret = getent(&icap, &ilen, db_p, fd, tc, depth+1,
431 NULL);
432 newicap = icap; /* Put into a register. */
433 newilen = ilen;
434 if (iret != 0) {
435 /* an error */
436 if (iret < -1) {
437 if (myfd)
|
438 (void)_libc_close(fd);
|
| 438 (void)_close(fd); |
439 free(record);
440 return (iret);
441 }
442 if (iret == 1)
443 tc_not_resolved = 1;
444 /* couldn't resolve tc */
445 if (iret == -1) {
446 *(s - 1) = ':';
447 scan = s - 1;
448 tc_not_resolved = 1;
449 continue;
450
451 }
452 }
453 /* not interested in name field of tc'ed record */
454 s = newicap;
455 for (;;)
456 if (*s == '\0')
457 break;
458 else
459 if (*s++ == ':')
460 break;
461 newilen -= s - newicap;
462 newicap = s;
463
464 /* make sure interpolated record is `:'-terminated */
465 s += newilen;
466 if (*(s-1) != ':') {
467 *s = ':'; /* overwrite NUL with : */
468 newilen++;
469 }
470
471 /*
472 * Make sure there's enough room to insert the
473 * new record.
474 */
475 diff = newilen - tclen;
476 if (diff >= r_end - rp) {
477 u_int pos, tcpos, tcposend;
478 size_t newsize;
479
480 pos = rp - record;
481 newsize = r_end - record + diff + BFRAG;
482 tcpos = tcstart - record;
483 tcposend = tcend - record;
484 record = reallocf(record, newsize);
485 if (record == NULL) {
486 errno = ENOMEM;
487 if (myfd)
|
488 (void)_libc_close(fd);
|
| 488 (void)_close(fd); |
489 free(icap);
490 return (-2);
491 }
492 r_end = record + newsize;
493 rp = record + pos;
494 tcstart = record + tcpos;
495 tcend = record + tcposend;
496 }
497
498 /*
499 * Insert tc'ed record into our record.
500 */
501 s = tcstart + newilen;
502 bcopy(tcend, s, rp - tcend);
503 bcopy(newicap, tcstart, newilen);
504 rp += diff;
505 free(icap);
506
507 /*
508 * Start scan on `:' so next cgetcap works properly
509 * (cgetcap always skips first field).
510 */
511 scan = s-1;
512 }
513
514 }
515 /*
516 * Close file (if we opened it), give back any extra memory, and
517 * return capability, length and success.
518 */
519 if (myfd)
|
520 (void)_libc_close(fd);
|
| 520 (void)_close(fd); |
521 *len = rp - record - 1; /* don't count NUL */
522 if (r_end > rp)
523 if ((record =
524 reallocf(record, (size_t)(rp - record))) == NULL) {
525 errno = ENOMEM;
526 return (-2);
527 }
528
529 *cap = record;
530 if (tc_not_resolved)
531 return (1);
532 return (0);
533}
534
535static int
536cdbget(capdbp, bp, name)
537 DB *capdbp;
538 char **bp, *name;
539{
540 DBT key, data;
541
542 key.data = name;
543 key.size = strlen(name);
544
545 for (;;) {
546 /* Get the reference. */
547 switch(capdbp->get(capdbp, &key, &data, 0)) {
548 case -1:
549 return (-2);
550 case 1:
551 return (-1);
552 }
553
554 /* If not an index to another record, leave. */
555 if (((char *)data.data)[0] != SHADOW)
556 break;
557
558 key.data = (char *)data.data + 1;
559 key.size = data.size - 1;
560 }
561
562 *bp = (char *)data.data + 1;
563 return (((char *)(data.data))[0] == TCERR ? 1 : 0);
564}
565
566/*
567 * Cgetmatch will return 0 if name is one of the names of the capability
568 * record buf, -1 if not.
569 */
570int
571cgetmatch(buf, name)
572 char *buf, *name;
573{
574 register char *np, *bp;
575
576 /*
577 * Start search at beginning of record.
578 */
579 bp = buf;
580 for (;;) {
581 /*
582 * Try to match a record name.
583 */
584 np = name;
585 for (;;)
586 if (*np == '\0')
587 if (*bp == '|' || *bp == ':' || *bp == '\0')
588 return (0);
589 else
590 break;
591 else
592 if (*bp++ != *np++)
593 break;
594
595 /*
596 * Match failed, skip to next name in record.
597 */
598 bp--; /* a '|' or ':' may have stopped the match */
599 for (;;)
600 if (*bp == '\0' || *bp == ':')
601 return (-1); /* match failed totally */
602 else
603 if (*bp++ == '|')
604 break; /* found next name */
605 }
606}
607
608
609
610
611
612int
613cgetfirst(buf, db_array)
614 char **buf, **db_array;
615{
616 (void)cgetclose();
617 return (cgetnext(buf, db_array));
618}
619
620static FILE *pfp;
621static int slash;
622static char **dbp;
623
624int
625cgetclose()
626{
627 if (pfp != NULL) {
628 (void)fclose(pfp);
629 pfp = NULL;
630 }
631 dbp = NULL;
632 gottoprec = 0;
633 slash = 0;
634 return(0);
635}
636
637/*
638 * Cgetnext() gets either the first or next entry in the logical database
639 * specified by db_array. It returns 0 upon completion of the database, 1
640 * upon returning an entry with more remaining, and -1 if an error occurs.
641 */
642int
643cgetnext(bp, db_array)
644 register char **bp;
645 char **db_array;
646{
647 size_t len;
648 int status, i, done;
649 char *cp, *line, *rp, *np, buf[BSIZE], nbuf[BSIZE];
650 u_int dummy;
651
652 if (dbp == NULL)
653 dbp = db_array;
654
655 if (pfp == NULL && (pfp = fopen(*dbp, "r")) == NULL) {
656 (void)cgetclose();
657 return (-1);
658 }
659 for(;;) {
660 if (toprec && !gottoprec) {
661 gottoprec = 1;
662 line = toprec;
663 } else {
664 line = fgetln(pfp, &len);
665 if (line == NULL && pfp) {
666 (void)fclose(pfp);
667 if (ferror(pfp)) {
668 (void)cgetclose();
669 return (-1);
670 } else {
671 if (*++dbp == NULL) {
672 (void)cgetclose();
673 return (0);
674 } else if ((pfp =
675 fopen(*dbp, "r")) == NULL) {
676 (void)cgetclose();
677 return (-1);
678 } else
679 continue;
680 }
681 } else
682 line[len - 1] = '\0';
683 if (len == 1) {
684 slash = 0;
685 continue;
686 }
687 if (isspace((unsigned char)*line) ||
688 *line == ':' || *line == '#' || slash) {
689 if (line[len - 2] == '\\')
690 slash = 1;
691 else
692 slash = 0;
693 continue;
694 }
695 if (line[len - 2] == '\\')
696 slash = 1;
697 else
698 slash = 0;
699 }
700
701
702 /*
703 * Line points to a name line.
704 */
705 i = 0;
706 done = 0;
707 np = nbuf;
708 for (;;) {
709 for (cp = line; *cp != '\0'; cp++) {
710 if (*cp == ':') {
711 *np++ = ':';
712 done = 1;
713 break;
714 }
715 if (*cp == '\\')
716 break;
717 *np++ = *cp;
718 }
719 if (done) {
720 *np = '\0';
721 break;
722 } else { /* name field extends beyond the line */
723 line = fgetln(pfp, &len);
724 if (line == NULL && pfp) {
725 (void)fclose(pfp);
726 if (ferror(pfp)) {
727 (void)cgetclose();
728 return (-1);
729 }
730 } else
731 line[len - 1] = '\0';
732 }
733 }
734 rp = buf;
735 for(cp = nbuf; *cp != '\0'; cp++)
736 if (*cp == '|' || *cp == ':')
737 break;
738 else
739 *rp++ = *cp;
740
741 *rp = '\0';
742 /*
743 * XXX
744 * Last argument of getent here should be nbuf if we want true
745 * sequential access in the case of duplicates.
746 * With NULL, getent will return the first entry found
747 * rather than the duplicate entry record. This is a
748 * matter of semantics that should be resolved.
749 */
750 status = getent(bp, &dummy, db_array, -1, buf, 0, NULL);
751 if (status == -2 || status == -3)
752 (void)cgetclose();
753
754 return (status + 1);
755 }
756 /* NOTREACHED */
757}
758
759/*
760 * Cgetstr retrieves the value of the string capability cap from the
761 * capability record pointed to by buf. A pointer to a decoded, NUL
762 * terminated, malloc'd copy of the string is returned in the char *
763 * pointed to by str. The length of the string not including the trailing
764 * NUL is returned on success, -1 if the requested string capability
765 * couldn't be found, -2 if a system error was encountered (storage
766 * allocation failure).
767 */
768int
769cgetstr(buf, cap, str)
770 char *buf, *cap;
771 char **str;
772{
773 register u_int m_room;
774 register char *bp, *mp;
775 int len;
776 char *mem;
777
778 /*
779 * Find string capability cap
780 */
781 bp = cgetcap(buf, cap, '=');
782 if (bp == NULL)
783 return (-1);
784
785 /*
786 * Conversion / storage allocation loop ... Allocate memory in
787 * chunks SFRAG in size.
788 */
789 if ((mem = malloc(SFRAG)) == NULL) {
790 errno = ENOMEM;
791 return (-2); /* couldn't even allocate the first fragment */
792 }
793 m_room = SFRAG;
794 mp = mem;
795
796 while (*bp != ':' && *bp != '\0') {
797 /*
798 * Loop invariants:
799 * There is always room for one more character in mem.
800 * Mp always points just past last character in mem.
801 * Bp always points at next character in buf.
802 */
803 if (*bp == '^') {
804 bp++;
805 if (*bp == ':' || *bp == '\0')
806 break; /* drop unfinished escape */
807 if (*bp == '?') {
808 *mp++ = '\177';
809 bp++;
810 } else
811 *mp++ = *bp++ & 037;
812 } else if (*bp == '\\') {
813 bp++;
814 if (*bp == ':' || *bp == '\0')
815 break; /* drop unfinished escape */
816 if ('0' <= *bp && *bp <= '7') {
817 register int n, i;
818
819 n = 0;
820 i = 3; /* maximum of three octal digits */
821 do {
822 n = n * 8 + (*bp++ - '0');
823 } while (--i && '0' <= *bp && *bp <= '7');
824 *mp++ = n;
825 }
826 else switch (*bp++) {
827 case 'b': case 'B':
828 *mp++ = '\b';
829 break;
830 case 't': case 'T':
831 *mp++ = '\t';
832 break;
833 case 'n': case 'N':
834 *mp++ = '\n';
835 break;
836 case 'f': case 'F':
837 *mp++ = '\f';
838 break;
839 case 'r': case 'R':
840 *mp++ = '\r';
841 break;
842 case 'e': case 'E':
843 *mp++ = ESC;
844 break;
845 case 'c': case 'C':
846 *mp++ = ':';
847 break;
848 default:
849 /*
850 * Catches '\', '^', and
851 * everything else.
852 */
853 *mp++ = *(bp-1);
854 break;
855 }
856 } else
857 *mp++ = *bp++;
858 m_room--;
859
860 /*
861 * Enforce loop invariant: if no room left in current
862 * buffer, try to get some more.
863 */
864 if (m_room == 0) {
865 size_t size = mp - mem;
866
867 if ((mem = reallocf(mem, size + SFRAG)) == NULL)
868 return (-2);
869 m_room = SFRAG;
870 mp = mem + size;
871 }
872 }
873 *mp++ = '\0'; /* loop invariant let's us do this */
874 m_room--;
875 len = mp - mem - 1;
876
877 /*
878 * Give back any extra memory and return value and success.
879 */
880 if (m_room != 0)
881 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL)
882 return (-2);
883 *str = mem;
884 return (len);
885}
886
887/*
888 * Cgetustr retrieves the value of the string capability cap from the
889 * capability record pointed to by buf. The difference between cgetustr()
890 * and cgetstr() is that cgetustr does not decode escapes but rather treats
891 * all characters literally. A pointer to a NUL terminated malloc'd
892 * copy of the string is returned in the char pointed to by str. The
893 * length of the string not including the trailing NUL is returned on success,
894 * -1 if the requested string capability couldn't be found, -2 if a system
895 * error was encountered (storage allocation failure).
896 */
897int
898cgetustr(buf, cap, str)
899 char *buf, *cap, **str;
900{
901 register u_int m_room;
902 register char *bp, *mp;
903 int len;
904 char *mem;
905
906 /*
907 * Find string capability cap
908 */
909 if ((bp = cgetcap(buf, cap, '=')) == NULL)
910 return (-1);
911
912 /*
913 * Conversion / storage allocation loop ... Allocate memory in
914 * chunks SFRAG in size.
915 */
916 if ((mem = malloc(SFRAG)) == NULL) {
917 errno = ENOMEM;
918 return (-2); /* couldn't even allocate the first fragment */
919 }
920 m_room = SFRAG;
921 mp = mem;
922
923 while (*bp != ':' && *bp != '\0') {
924 /*
925 * Loop invariants:
926 * There is always room for one more character in mem.
927 * Mp always points just past last character in mem.
928 * Bp always points at next character in buf.
929 */
930 *mp++ = *bp++;
931 m_room--;
932
933 /*
934 * Enforce loop invariant: if no room left in current
935 * buffer, try to get some more.
936 */
937 if (m_room == 0) {
938 size_t size = mp - mem;
939
940 if ((mem = reallocf(mem, size + SFRAG)) == NULL)
941 return (-2);
942 m_room = SFRAG;
943 mp = mem + size;
944 }
945 }
946 *mp++ = '\0'; /* loop invariant let's us do this */
947 m_room--;
948 len = mp - mem - 1;
949
950 /*
951 * Give back any extra memory and return value and success.
952 */
953 if (m_room != 0)
954 if ((mem = reallocf(mem, (size_t)(mp - mem))) == NULL)
955 return (-2);
956 *str = mem;
957 return (len);
958}
959
960/*
961 * Cgetnum retrieves the value of the numeric capability cap from the
962 * capability record pointed to by buf. The numeric value is returned in
963 * the long pointed to by num. 0 is returned on success, -1 if the requested
964 * numeric capability couldn't be found.
965 */
966int
967cgetnum(buf, cap, num)
968 char *buf, *cap;
969 long *num;
970{
971 register long n;
972 register int base, digit;
973 register char *bp;
974
975 /*
976 * Find numeric capability cap
977 */
978 bp = cgetcap(buf, cap, '#');
979 if (bp == NULL)
980 return (-1);
981
982 /*
983 * Look at value and determine numeric base:
984 * 0x... or 0X... hexadecimal,
985 * else 0... octal,
986 * else decimal.
987 */
988 if (*bp == '0') {
989 bp++;
990 if (*bp == 'x' || *bp == 'X') {
991 bp++;
992 base = 16;
993 } else
994 base = 8;
995 } else
996 base = 10;
997
998 /*
999 * Conversion loop ...
1000 */
1001 n = 0;
1002 for (;;) {
1003 if ('0' <= *bp && *bp <= '9')
1004 digit = *bp - '0';
1005 else if ('a' <= *bp && *bp <= 'f')
1006 digit = 10 + *bp - 'a';
1007 else if ('A' <= *bp && *bp <= 'F')
1008 digit = 10 + *bp - 'A';
1009 else
1010 break;
1011
1012 if (digit >= base)
1013 break;
1014
1015 n = n * base + digit;
1016 bp++;
1017 }
1018
1019 /*
1020 * Return value and success.
1021 */
1022 *num = n;
1023 return (0);
1024}
1025
1026
1027/*
1028 * Compare name field of record.
1029 */
1030static int
1031nfcmp(nf, rec)
1032 char *nf, *rec;
1033{
1034 char *cp, tmp;
1035 int ret;
1036
1037 for (cp = rec; *cp != ':'; cp++)
1038 ;
1039
1040 tmp = *(cp + 1);
1041 *(cp + 1) = '\0';
1042 ret = strcmp(nf, rec);
1043 *(cp + 1) = tmp;
1044
1045 return (ret);
1046}
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